I have no idea. I do know that the red starts coming into the comb real quick with them. At a month we were able to tell that one of the little girls was going to be named Vin- as in coq a vin. The feed store threw in an extra pullet with the perchase of six so it's not like we payed for the little guy. I seem to remember that they all had different amounts of yellow on the head.
Very Sneaky! Love the title! I'm glad I'm not the only one with that problem sometimes! I told my daughter I thought maybe I had chicken cooties, so no one would hardly answer me!
I'm not sure about the australorps having a sex link. I would keep an eye on their combs. In most chicks, the males combs turn a redder color, and are noticably larger than the females. I hope this helps you out some.